Dynamic Propeller Balancer Build

Hi All,

I recently build a Dynamic Propeller Balancer, and much to my surprise, it worked better than I ever expected. As such, I decided to document the build, create a couple of videos on its usage, and publish my results for others that would want to replicate this "rig."

The software and Idea of this device came from a diydrones post by Frank Albertsma, who did an amazing job at writing the initial software. You can read his post, as well as some of the details and links to software here:

Below, you can see the "rig" that I build, the circuit diagram I used to create my version of this great tool, and a few videos which I will post, that provide every detail of this build, as well as instruction as to how to properly tune the device, and use it with great results. I am hoping that others will build it, improve it, and maybe even make improvements to the code etc.

Recently I decided to take on the project, and basically re-write the whole thing from scratch! Here are some of the features of this software which I developed (Should still be considered work in progress, as I am constantly adding/revising it, and LOVE feedback!)

-Real time Analysis of Imbalance, with real time feedback on a polar graph of the direction of Imbalance.

-Very fast updates, using a Teensy (and a pro-mini) and an ADXL345, both running at "full blast :-)" at 115200 Baud to PC.

-Real time Vibration Analysis using a real-time graphic plot for immediate visual feedback of Vibration levels and Configs.

-Comprehensive "Four Point Balance" functions with graphical and accurate feedback

-Real time FFT analysis! Shows CLEARLY vibration levels, as well as frequency of vibration.

-ESC control functions, that allows the operator to fully control and program an ESC for experimentation etc.

Below, you can see some photos of the "rig" as well as a PCB schematic I used to create the very simple circuit board. The device uses an Arduino Pro Mini, along with an ADXL345 Accelerometer to achieve it's great results. There is also a few resistors, an PNP transistor, and a Photo-detector pair, that detects the RPM and location of the blades. Again, all details provided in the schematic below. Most of the parts were cut on my CNC machine, including the small circuit board I used. One could easily do this with a perfboard, and a few blocks of spare wood.

Be on the lookout for a set of videos that will fully describe it's operation.

Cheers!

EDIT: Attached the Gerber Files for the VERY simple Circuit Board...

EDIT: 3/31/2015: Initial Release of DPBalance Program is here!
More information on the build, and how to initially use it is posted on the following Thread:

EDIT: 5/15/15 ==>PRE- RELEASE 1.3: This one has an installer since some folks had issues with missing DLL's. Some cosmetic things to fix, but wanted to have folks using the DSP functionality, CAUSE IT IS AWESOME! :-) Watch the video below to see how to use DSP filtering....

ALSO: POSTED NEW circuit board with Teensy Support! I have also attached the Full gerber Files which you can simply upload to OSHPark if you want to make a board....if you go this route, please let me know, so that I can send you the .hex file for the Teensy!

Once loaded, simply choose the teensy.hex file below, attach your teensy to your USB port, and upload the firmware. You can then use the DP windows application to connect to your teensy and create some perfectly balanced Props! If there are any issues, please ask...

So to clarify, ADXL345 is Correct, the pro-mini I use is a 5V version, as they come in 3V and 5V. 5V also has enough current to supply the small Laser pointer I have mounted, so you do not need a separate 5V supply...this is why I use it. Hunt them down on Ebay, MUCH cheaper!

So you either stick to 5V or 3V, but I chose 5V for both....your choice...

Also, the ADXL345 I linked below, has an on-board regulator, that will also allow you to run it off 5V. The one from Sparkfun, besides being 3 times more expensive, requires 3 V.

So to clarify, ADXL345 is Correct, the pro-mini I use is a 5V version, as they come in 3V and 5V. 5V also has enough current to supply the small Laser pointer I have mounted, so you do not need a separate 5V supply...this is why I use it. Hunt them down on Ebay, MUCH cheaper!

So you either stick to 5V or 3V, but I chose 5V for both....your choice...

Also, the ADXL345 I linked below, has an on-board regulator, that will also allow you to run it off 5V. The one from Sparkfun, besides being 3 times more expensive, requires 3 V.

Using just the transistor you will then need a small laser pointer to trigger it, as it works great with that also, and you do not need the infrared....like I said,anything will really work.

Also, when mounting your accelerometer, hit the read sensor button on the software, and make sure you get as close to 0 readings as possible ( around +,- 2 or so is OK....but do not mount it on some weird angle! keep it flat!). This will confirm that you are mounting it level, and it will help in the calibration and overall accuracy of your rig....so the more level the better when it comes to mounting it.